Page:Encyclopædia Britannica, Ninth Edition, v. 22.djvu/143

 S K Y S L A 127 the administration of the district. There is a considerable export of grain and cattle from the district, which is fertile and has many villages of from 3000 to 5000 inhabitants. In the 14th century Skvira was a far more important town than now, but the wars destroyed it, so that two centuries later it was left uninhabited ; it was settled anew by Prince R6zinski, and the population slowly reached the number of 1000 by the end of the last century. The town has grown rapidly during the last ninety years. SKYE, the largest island of the Inner Hebrides, Scot- land, is situated between the mainland of Inverness-shire, within which county it is included, and the group of the Outer Hebrides. It lies between 57 1' 12" and 57 42' 30" N. lat. and 5 38' 50" and 6 47' 8" W. long. It is separated from the mainland at its eastern corner by Loch Alsh and Kyle Rhea, the channel at the narrowest point having a breadth of only about 3 furlongs. Southwards Kyle Rhea widens out into the Sound of Sleat, and to the west of Loch Alsh there is a sudden widening of the gap to the extent of about 9 miles. Along the eastern shore are the islands of Pabba, Scalpa, Raasay, Fladda, and Rona. The Minch separating Lewis and the mainland bounds Skye on the north, and the Little Minch to the north- west separates it from North Uist and Harris. The total area is 411,703 acres or 643 square miles. The coast- line is extremely irregular, abounding in inlets of a great variety of form and size, and in the north and west it is wildly precipitous. The island is naturally divided into three parts, each marked off by its distinctive geology and scenery. By much the largest division lies to the north of a line drawn from Loch Brittle to the head of Loch Sligachan. In this area the rocks are almost wholly varieties of basalt, disposed in nearly horizontal sheets, which give a singular tabular shape to the hills and ter- raced forms to the slopes. To the east of Loch Snizort are the basaltic groups which include the Storr Rock (2360 feet), with its curious columns, and the Quiraing (1774 feet), with its verdant platform in the centre of a range of rugged cliffs. In the north-west are Macleod's Tables (1601 feet) and .some smaller summits. The central division may be defined along its southern border by a line drawn from Loch Slapin to Broadford. Its rocks are almost wholly of volcanic origin, and belong mainly to two groups, each characterized by its peculiar mountain outlines. The dark gabbros and dolerites form the jagged ridges of the Cuillins, and reach in Scuir-na-Gillean a height of 3167 feet, and in Blaaven 3042 feet. To the north-east of the Cuillins tower in striking contrast the pyramidal Red Mountains, consisting of granite, syenite, quartz -porphyry, and various allied rocks, and reaching in Glamaig a height of 2670 feet. The third division in- cludes all the rest of the island, and consists of two toler- ably distinct tracts. The more northerly of these lies along the base of the Red Hills, and forms the narrow part of Skye between Strathaird and Broadford Bay. It is composed mainly of Secondary rocks (Lias and Oolite), through which the eruptive masses of the Red Hills have been thrust. The more southerly part comprises the dis- trict of Sleat, and consists of red sandstone (Torridon sand- stone or Cambrian), rising in Scuir-na-Coinnich to 2401 feet, and of various crystalline schists and quartzites which stretch from Loch Alsh along the Sound of Sleat to the southern point of the island. A considerable tract of lime- stone lies in the centre of Strath Parish, some of which has been altered by the eruptive rocks into a pure white marble. There are several inland lochs of considerable size, the largest being Loch Coruisk, remarkable for the gloomy grandeur of its situation in the heart of the Ciiillins. On account of the damp climate the land is better adapted for rearing sheep and cattle than for tillage. A large number of cattle of the West Highland breed are grazed on the moors. The sheep are principally'blackfaced, but some Cheviots are also kept. The greater portion of the inhabitants are crofters, who inhabit chiefly miserable huts with a fireplace in the middle of the floor, the smoke escaping by a hole in the roof. The number of crofts in Skye, according to the report of the Crofters Commission 1884, was 2051. The number of families ejected by decrees from their holdings between 1840 and 1860 was 5012, representing a popula- tion of 25,060, and between 1860 and 1883 1948, representing a population of 9740. Many of the crofters support themselves partly by fishing. Iii the Loch Carrou and Skye district the number of boats in 1884 was 950, employing 2904 men and boys. From 20,627 in 1821 the population of Skye had increased to 23,082 in 1841, but by 1871 it had decreased to 17,330 and in 1881 to 16,889, of whom 16,099 were Gaelic-speaking. The number of females was 8903 and of males 7986. Portree, the principal town, has a population of 893. See, besides the works referred to under HEBRIDES, Alexander Smith's Summer in Skye, 1865 ; Robert Buchanan's The Jfebrid Jsles, 1883 ; and Report of the Crofters Commission, 1881* SLANDER. See LIBEL. SLATE is an argillaceous rock of various colours blue, green, purple, grey, and black and a peculiar structure by which it readily splits into thin plates or lamina?. It is of sedimentary origin, being primarily deposited on ocean floors as fine mud formed by the waste and denuda- tion of pre-existing rocks, and afterwards compressed, hardened, and altered into compact rock. Slate beds occur mainly in the Cambrian, Silurian, and Devonian formations frequently alternating with bands of grit and limestone, or interstratified with felspathic lava or ashes and, being tilted up from their original horizontal or nearly horizontal position, stretch across wide districts in a series of undulations, which rise to the surface in crests, or dip into troughs underground and form angles of every inclina- tion with the horizon. 1 Slate rock splits along cleavage planes which are dis- tinct from and independent of original stratification. These planes are, as a rule, vertical or highly inclined, and intersect the lines of bedding at various angles, but some- times coincide with them. The strike of cleavage is generally parallel with that of the slate beds, and a uni- form direction is often maintained over wide areas, as in North Wales, where it is nearly north-north-east and south- south-west, while in Shropshire it is north-east and south- west, and in Pembrokeshire north-by-west and south-by-east. This peculiar cleavage structure is believed to be the result of a combination of intense forces, chiefly lateral pressure acting at right angles to the planes of cleavage. Contraction, compression, shearing, and other powerful forces have caused great disturbances in slate beds, since they were first thrown down as fine sediment, and the results are seen in the foldings, contortions, fissures, rents, and dislocations that now exist. The fissures often follow well-defined courses and form divisional planes termed joints, some running parallel with the strike and called strike joints, others running in the direction of the dip and called dip joints. Dykes of greenstone and other 1 The following table shows the older sedimentary formations in which slate beds mainly occur, in the order of superposition : Primary or Palaeozoic Rocks. Permian. Magnesian limestone, marls, sandstones, &c. Carboniferous. Coal measures, limestone, slate, &c. Devonian. Old red sandstone, slates, &c. ( Ludlow group. Upper. < Wenlock. ( Upper Llandovery. ' Lower Llandovery. Caradoc and Bala. Llaudeilo. .Lower. -J Arenig. Tremadoc. Lingula flags. .. Menevian beds. Cambrian. Cambrian grits, conglomerates, and slates. Primitive crystalline rocks. Gneiss, schists, &c. Silurian.